Newark Mayor Cory Booker, perhaps New Jersey's highest-profile Democrat, has ruled out a bid for governor next year and is eyeing a run for U.S. Senate in 2014.

The decision, announced Thursday on Twitter, means Booker has decided against a possible campaign against Republican Gov. Chris Christie. But, depending on how things play out, he could find himself in a Democratic primary race against Sen. Frank Lautenberg, who is 88 and declined to talk Thursday about his political future.

"Let there be no doubt, I will complete my full second term as mayor," Booker said in a statement posted on Facebook and linked to on Twitter. "As for my political future, I will explore the possibility of running for the United States Senate in 2014."

A Stanford-educated Rhodes scholar who grew up in suburban Harrington Park, N.J., Booker is the son of civil rights activists who were among the first black executives at IBM. He got his law degree from Yale Law School, then moved to one of Newark's most notoriously violent housing projects.